Methanohalophilus oregonense sp. nov., a methylotrophic methanogen from an alkaline, saline aquifer

摘要: Methanohalophilus oregonense WAL1T (= OGI 99T = DSM 5435T) (T type strain) was isolated from an anoxic aquifer (pH 10, with 100 g of dissolved solids per liter pore water) 3 m deep near Alkali Lake, alkaline, desert lake in south central Oregon. An examination the subsurface sediments revealed no methanogens that were capable growth on methanogenic substrates, such as H2-CO2, formate, or acetate, which is consistent results other studies hypersaline, sulfate-containing environments. Strain grew trimethylamine and slowly methanol dimethylsulfide, but did not catabolize acetate. The cells irregular coccoids (diameter, 1 to 1.5 μm), growing liquid media also formed clumps 2 15 more cells. mesophilic required one vitamins present yeast extract. Like only previously described strain alkaliphilic, methylotrophic methanogen (Methanohalophilus zhilinae WeN5T), most rapidly medium moderate salinity; well presence 0.1 1.4 M Na+ at concentration 0.35 (specific rate, h-1). Best occurred about 50 mM Mg2+ a pH 8.4 9.0. K+ appeared be required, 13 130 supporting rapid growth. guanine-plus-cytosine content DNA 40.9 ± mol%.